1. Field of the Invention
This invention relates generally to apparatus for detecting water in fuel, and more particularly to a device which is connected to a fuel nozzle or gas tank and has a transparent tubular portion with a color change chemical paste composition disposed therein to visually detect the presence of water in the fuel being pumped.
2. Brief Description of the Prior Art
Fuel storage tanks at gas service stations are subject to being diluted by water. A motorist has no way of knowing the quality of the fuel being pumped into their vehicle until they begin to have problems with the engine. The water diluted fuel may cause knocking and pinging or stalling of the engine, and in some instances may damage the carburetor, fuel pump, fuel injectors, fuel system and internal engine components, resulting in costly repairs. If water is detected in the fuel, the gas tank must be drained.
There are several patents which disclose various devices for detecting contaminated fuel.
Gray et al, U.S. Pat. No. 4,517,547 discloses a sensing circuit connected with a probe capacitor positioned within a fuel tank which detects excessive water in the fuel of a vehicle. As the water content increases, the capacitance of the variable capacitor probe increases thereby reducing the magnitude of a rectified current. As the magnitude of the rectified current decreases below the magnitude of a known current, the sensing circuit produces a signal to turn on a warning light on the dash of the vehicle.
Sutton, U.S. Pat. No. 4,638,305 discloses an electrically conductive metal probe or siphon tube coupled to an electronic detection circuit which detects the presence of water in diesel or other fuel oil. The electrical circuit is responsive to either low resistance or high capacitance between the probe and ground. The probe makes a resistive coupling to the fuel container when accumulated water touches the probe. When insulating deposits from the fuel coat the probe, capacitive coupling will occur between the probe and accumulated water.
It is known in the art to coat the lower end of a gasoline storage tank measuring stick or gauge with a color change chemical paste composition. The gauge is lowered into the storage tank and then removed. The lower portion of the coated gauge will change color to show the depth of a water/fuel mixture.
Chemical paste compositions which change color in the presence of water are known in the art. The present invention, in a preferred embodiment, utilizes a commercially available color change chemical paste composition, but does not attempt to claim a color change chemical paste composition per se. One example of a commercially available color change chemical paste suitable for use is sold by Kolor Kut Products, Inc., of Houston, Tex. under the trademark "KOLOR KUT".TM..
Melpolder et al, U.S. Pat. No. 4,699,885, and Melpolder, U.S. Pat. Nos. 4,578,357 and 4,717,671, hereby incorporated by reference, also disclose suitable color change chemical paste compositions.
These types of color change chemical paste compositions are used to coat the lower end of a gasoline storage tank measuring stick or gauge which is used to test the fuel stored in the storage tank. The gauge is lowered into the storage tank and then removed. The lower portion of the coated gauge will change color to show the depth of a water/fuel mixture. In some cases, the stored fuel is not tested, or only occasionally tested, and the motorist has no way of knowing whether the fuel he or she is putting into the vehicle has been tested.
The present invention is distinguished over the prior art in general, and these patents in particular by a device adapted to be placed between a fuel storage tank and a fuel container into which the fuel is to be pumped, for example on a fuel pump nozzle, for detecting the presence of water in the fuel being pumped. The device has a tubular member with an inlet for receiving a portion of the fuel being pumped, an outlet for discharging the portion of fuel conducted through the tubular member, and a transparent portion disposed between the inlet and outlet. A chemical paste composition containing a water responsive indicator dye is disposed in the transparent portion of the tubular member to contact the portion of fuel conducted through the tubular member and produces a visually noticeable color change indicating the presence of water in the fuel being pumped.